I. Field of the Invention
The present invention relates generally to small article packaging devices and, more particularly, to such a device in which the conveyor strip forms a part of the final package.
II. Description of the Prior Art
There have been many previously known small article packaging devices. While these prior devices can be utilized to package any desired small article, such devices have particular utility for packaging pills and other medicines. Such medicines are typically packaged in the unit doses for easy, accurate and simple disbursement in hospitals and medical clinics.
Although these previously known machines vary in form, typically they comprise a conveyor system which carries a first strip of the packaging material. The articles packaged by these prior devices are arranged by a feeder on the packaging material and thereafter the packaging material is sealed either to itself or to another strip of packaging material which encloses the article in the material. The conveyor system then moves the sealed articles to a cutting apparatus which severs the strip into packages, each containing the desired number of articles.
These previously known packaging machines suffer several disadvantages unknown to the present invention. One such disadvantage is that these previous machines are unduly complex and, accordingly, expensive in construction. In particular, the previously known feeders for loading the articles onto the conveyor material oftentimes jams up or otherwise malfunctions which renders the entire machine inoperable.
The conveyor for carrying the packaging strip is also an expensive component in these prior devices. Moreover, these conveyors require extensive periodic maintenance which also necessitates a shut down of the packaging device.
Another disadvantage of these previously known packaging achines is that the means for feeding the closure strip over the packaging strip must be precisely synchronized with the conveyor which carries the packaging strip. Oftentimes, either the conveyor or the means for feeding the closure strip over the packaging strip malfunctions which again necessitates shut down and repair of the packaging device.
Present "unit dose packaging38 of pills and capsules for patient use in hospitals takes two forms. The first, packaging of high volume drugs, is done by large packaging machines usually located in the plants of the drug manufacturer. The second, too small to justify packaging at the plant but large enough to justify special packaging at the hospital, is usually done by a mobile packaging unit which is delivered periodically to the hospital pharmacy. Typically, such a mobile unit might visit a hospital once every few months and package 50,000-100,000 pills. Typically this total might also include a few hundred unit doses of many little-used pills up to several thousand unit doses of other pills.
Several serious problems attend the use of such mobile units. First, there are the traveling expenses of the operator. Second, time considerations dictate that the packaging machine be built for high speed operation with the accompanying increased risk of malfunction. In fact, the machines presently being used require an operator with some skills in machine repair. A third problem is that each time a different pill is to be packaged, the machine, particularly the feed hopper, must be cleaned and the printing stencil must be changed. This leads to a considerable down-time of the machine during which a skilled machine operator is occupied with tasks which could easily be carried out by unskilled people.